Original character by Rog Rockbe.
Her name is literally 助手 (joshu, helper/assistant). Regarding the romanization, the artist has used "Josh" in several pieces. See pixiv #43175144 and pixiv #45907435.
She has Long Hair over one eye and usually wears a Lab Coat, red bikini top, Thighhighs, undone Belt, and large Wrist Cuffs.